Resiliently supported shear plate

ABSTRACT

A dry-shaving apparatus having a single driving shaft and at least one shaving head which is actuated by the driving shaft and is adapted to be axially depressed and comprises a shear plate and a cooperating movable cutter member which is maintained in resilient engagement with the shear plate, the central shear plate being also supported by a separate, axially adjustable spring.

United States Patent [56] References Cited UNITED STATES PATENTS2,526,153 10/1950 Page.....

[72] Inventors FransZuurveen Emmaslngel, Eindhoven;

Eduard Willem Tletjens, Oliemolenstraat, Draehten, both of Netherlands[21 1 Appl. No. 852,305

30/4391 2,536,015 12/1950 Konrad........................ 30/43.6

FOREIGN PATENTS 6/1946 France [22] Filed Aug. 22, 1969 [45] PatentedNov. 30, 197i Great Britain................ 4/1959GreatBritain................

Primary Examiner-Robert C. Riordon Attorney-F rank R. Trifari [73]Assignee U.S. Philips Corporation New York, N.Y.

[32] Priority Aug. 31, 1968 [33] Netherlands MOTOR l- .1 1 .15 Mwwmw 0303 3W63 m 32 7. A J .n L m "ml P m m R m "3 A a m S m m D "m mr g n n mm w m mm Mn T m m a N m m ma ms m m 4 L l LM I..." C C q S LW E R8 U hFM H Um w w UH PAT-ENTEDNUV 30 I97! MOTOR f|g.1

INVENTOB FRANS ZUURVEEN EgUARD W. TIETJENS B AGENT RESILIENTLY SUPPORTEDSHEAR PLATE In the known dry shavers, an attempt to solve this problemincludes imparting to the shaving head a certain adaptability to thevarious shapes of the face, which adaptation is made possible by thevarious positions which the depressible shaving head can occupy relativeto the face. One of the factors which determine the resistance offeredby the skin in this adapting process is the force with which the cuttingmember is urged against the shear plate. In the known shaving apparatus,this resistance force produces a skin pressure which, as experience hasshown, is not always sufiicient to produce a close shave, with theresult during use of the known apparatus, that the shear plates areusually pressed into their extreme depressed positions thus instead ofadaptation of the shear plate to the various shapes of the face, theonly adaptivity factor remaining is the capacity for deformation of theshear plate itself.

It is an object of the present invention to eliminate or at leastobviate the above-mentioned drawback. Also the invention isdistinguished by the fact that the shear plate is supported by aseparate spring which enables the skin pressure to be increased.

In one embodiment of the invention, there is, for the resilient supportof the shear plate, a resiliently arranged driving shaft which actuatesthe cutter member, for which purpose the end of the driving shaft facingthe shear plate is in line or point contact with the surface of theshear plate facing the driving shaft.

Obviously the invention is not restricted to this embodiment relating toa resilient support of the shear plate with a thrust force confinedwithin a narrow limit. In other constructions, for example the springpressure is adjustable.

According to the above-mentioned embodiment the driving shaft is coupledwith the cutter member for driving same in rotation, the upper part ofthe driving shaft being shaped in the form of a coupling pin whichpasses with a certain amount of clearance through an aperture disposedcentrally of a blade-carrying holder part of the cutter member, whilethe free end of the coupling pin is maintained in engagement with theshear plate.

A highly advantageous embodiment in which at least two shaving heads areused which are engaged by their mutually adjacent side edges isdistinguished in that between the driving shaft and a motor couplingshaft there is established a coupling which is movable in at least twodirections; the lower part of the driving shaft has a noncircular crosssection and is coupled with the motor coupling shaft, and is arranged soas to ,be movable in a centrally disposed aperture in this motorcoupling shaft. This aperture extends from the free end of the motorcoupling shaft in the direction of length thereof, while the part of thedriving shaft situated between this lower part and the coupling pin isflexible or bendable relative to its own longitudinal axis.

The said movability of the driving shaft and the increase in the minimumnumber of shaving heads, which in addition are situated so as to becapable of a relative vertical sliding movement, increase theadaptability of the shaving plates to the various shapes of the face.

The invention will be described more fully with reverence to a drawing,which shows an embodiment and from which further advantageous featureswill become apparent:

FIG. I is a longitudinal sectional view of an embodiment according tothe invention; and

FIG. 2 is a perspective view of a spring system which may be used in theresilient support of the driving shaft.

Referring to FIG. 1, there is shown a group of shaving heads, which areoperated by a single driving shaft I.

In the embodiment shown there are four shaving heads 2, 3, 4 and 5,having shear plates 6, 7, 8 and 9 respectively, arranged concentricallyabout drive shaft 1 these plates are engaged to each other by theirmutually adjacent side edges which extend traversely to the axis of thedrive shaft. In this sectional view of FIG. 1, each shear plate has agenerally inverted U-shape and the inner sidewall of plate 6 merge intoa substantially flat plate 26. The shear plates 6, 7, 8 and 9 cooperatewith cutter members l0. l1, l2 and 13 respectively, Each cutter membercomprises at least one blade arm I4, l5, l6 and 17 and a blade-carryingholder part 18, I9, 20 or 21, respectively.

The driving shaft 1 comprises an upper part shaped in the form of acoupling pin 22, a lower part 24 cooperating with a motor coupling shaft23 and an intermediate middle part 25.

The coupling pin 22, has a cross-sectional area which is greater thanthat of the middle part 25 of the driving shaft 1, and which passes witha certain amount of clearance through apertures 27, 28, 29 and 30provided centrally of the bladecarrying holder parts l8, 19, 20 and 21respectively. The coupling pin 22 is engaged to these holder parts fordriving same in rotation about the drive shaft axis.

The end 31 of the coupling pin 22 facing the shear plate 6 has a curvedsurface which is maintained in engagement with that surface 26 of theplate which faces the driving shaft 1. The lower part 24 of the drivingshaft is axially movable in a central aperture 32 in the motor couplingshaft 23, which aperture 32 extends from the free end of shaft 23axially towards the motor (not shown) of the apparatus.

The middle part 25 of the driving shaft 1 is surrounded by a spring 33;the free end of the motor coupling shaft 23 and that end of the couplingpin 22 which faces the motor coupling shaft 23 form the abutments whichthe ends of the spring 33 resiliently engage. The spring 33 may be ahelical spring, as is shown in FIG. 1, but it may also take the form ofa spring system 34 (FIG. 2) comprising at leas three parallel connectedleaf springs 35. While the driving shaft 1 actuates at least two shavingheads, the middle part 25 of this shaft 1 is flexible or bendable aboutits own axis.

Obviously the invention is not restricted to embodiments in which theseparate spring which supports the central shear plate is situated so asto surround the driving shaft. Alternative constructions in which adriving shaft is resiliently supported, result in an additionalresilient support of the central shear plate. Furthermore, separatesprings of selectable spring pressure can be used in the invention toparticular advantage, because they enable the invention to besuccessfully applied to the shaving of highly sensitive parts of theface. The blade-car rying holder parts of the cutter members areresiliently supported by a spring system comprising separate springs 36,37, 38 and 39 connected in series.

We claim:

1. In a dry shaver including a housing, a rotary drive shaft, and ashaving head actuated by said shaft and comprising an axiallydepressible shear plate, first means resiliently urging the shear plateoutward relative to the housing and a cooperating cutter engaged anddriven by the shaft, the shaver further comprising second meansresiliently urging the shaft outward, the shaft having a first endengaging a portion of said shear plate and urging same outward.

2. In a dry shaver including a housing, a rotary drive shaft, and ashaving head actuated by said shaft and comprising a plurality ofconcentric, axially and independently depressible shear plates includinga central plate, a rotatable cutter operable with each shear plate, eachcutter having a central aperture through which extends said drive shaftin driving engagement, first resilient means urging each cutter outwardagainst its corresponding shear plate, separate second resilient meansurging the drive shaft outward, the shaft having a first end inengagement with the central shear plate and urging same out ward, theshear plates each engaged to the adjacent plate for limited relativemovement, whereby said plates are axially depressible against saidresilient means associated therewith.

3. Apparatus according to claim 1 wherein said first end of the shaftand the shear plate have adjacent surfaces that are engaged, thisengagement comprising at least point contact formed by at least onepoint of one of said surfaces in contact with the other surface.

4. Apparatus according to claim 3 wherein one of said engaging surfacesof the shaft and shear plate is substantially planar and the other iscurved.

5. Apparatus according to claim 1 and further comprising an electricmotor wherein said shaft has a second end remote from the first endwhich is rotatably driven by said motor, the cutter is rotatably drivenby the first end of the shaft, and both ends of the shaft are axiallymovable relative to the cutter and motor.

6. Apparatus according to claim 5 wherein said drive shaft has a thirdpart intermediate said first and second ends which is bendable relativeto its own axis.

7. Apparatus according to claim 2 wherein said shaft has a central partaxially spaced from said first end, that is bendable relative to its ownaxis.

8. Apparatus according to claim 2 wherein each resilient means comprisesat least one spring having a selected spring pressure applicable to thecomponents of the apparatus it con- IaCtS.

1. In a dry shaver including a housing, a rotary drive shaft, and ashaving head actuated by said shaft and comprising an axiallydepressible shear plate, first means resiliently urging the shear plateoutward relative to the housing and a cooperating cutter engaged anddriven by the shaft, the shaver further comprising second meansresiliently urging the shaft outward, the shaft having a first endengaging a portion of said shear plate and urging same outward.
 2. In adry shaver including a housing, a rotary drive shaft, and a shaving headactuated by said shaft and comprising a plurality of concentric, axiallyand independently depressible shear plates including a central plate, arotatable cutter operable with each shear plate, each cutter having acentral aperture through which extends said drive shaft in drivingengagement, first resilient means urging each cutter outward against itscorresponding shear plate, separate second resilient means urging thedrive shaft outward, the shaft having a first end in engagement with thecentral shear plate and urging same outward, the shear plates eachengaged to the adjacent plate for limited relative movement, wherebysaid plates are axially depressible against said resilient meansassociated therewith.
 3. Apparatus according to claim 1 wherein saidfirst end of the shaft and the shear plate have adjacent surfaces thatare engaged, this engagement comprising at least point contact formed byat least one point of one of said surfaces in contact with the othersurface.
 4. Apparatus according to claim 3 wherein one of said engagingsurfaces of the shaft and shear plate is substantially planar and theother is curved.
 5. Apparatus according to claim 1 and furthercomprising an electric motor wherein said shaft has a second end remotefrom the first end which is rotatably driven by said motor, the cutteris rotatably driven by the first end of the shaft, and both ends of theshaft are axially movable relative to the cutter and motor.
 6. Apparatusaccording to claim 5 wherein said drive shaft has a third partintermediate said first and second ends which is bendable relative toits own axis.
 7. Apparatus according to claim 2 wherein said shaft has acentral part axially spaced from said first end, that is bendablerelative to its own axis.
 8. Apparatus according to claim 2 wherein eachresilient means comprises at least one spring having a selected springpressure applicable to the components of the apparatus it contacts.